While figuring outhow to send mankind to Mars might be the hot topic of the day, there are still plenty of problems to solve on Earth, not least those presented by various humanitarian crises erupting across the globe. That's where the Aid Innovation Challenge comes in.

Part of the annual global humanitarian and development aid event AidEx, it is a Dragons' Den-style competition aimed at finding the next big invention that can help improve the way aid is delivered.

Here are the four finalists from this year's competition who will be taking to the stage in Brussels on November 16.

Not exactly rocket science: The Pak Flat Tank can be assembled by anyone(Credit: GreenCo Water)

The problem: Finding access to clean drinking water is one of the biggest problems during an emergency crisis. International guidelines suggest that each person should receive between 7.5 and 15 liters a day to cover their basic needs. However meeting these minimum standards is often difficult water sources sometimes miles away, and refugees lacking the means to store water at their shelters. Conventional water tanks, while useful, are expensive and heavy, and do not lend themselves to an agile setup.

The solution: As its name suggests, the Pak Flat Tank is a flat-pack water tank that comes in a box. Looking like something you might get off the shelves at Ikea, this 1,000-liter vessel weighs just 23kg and can be assembled by just about anyone with a screwdriver in under 10 minutes – no special tools or expertise required. 100 percent recyclable, its lightweight design makes it easy to transport and, according to the company, 1,200 of these tanks can easily fit in a C-17 cargo plane.

At present, the tanks have been installed at various elementary schools on the South Pacific island of Vanuatu following Cyclone Pam. It is also being trialed by Oxfam Australia and Australian Aid as part of their disaster-relief efforts in Fiji following Tropical Cyclone Winston.

The problem: For those of us living in developed countries, getting access to necessary healthcare treatment is something we often take for granted. This includes respiratory support for premature infants in the form of bubble continuous positive airway pressure (bCPAP) therapy. Parents in less developed countries are often not as fortunate. According to the World Health Organization (WHO), preterm birth complications are the leading cause of death for children under five worldwide, with the majority of them occurring in low-income countries.

The solution: The Pumani bCPAP is an affordable user-friendly respiratory device that costs 1/15th of the price of bCPAP devices in developed countries. New users can be trained to use it in less than one day, and according to the results of a clinical trial conducted at Queen Elizabeth Central Hospital (QECH) in Malawi, the survival rates of premature infants with respiratory problems rose to 71 percent, a 27 percent improvement over those treated with oxygen therapy.

The Maggie Shelter brings stability to the lives of displaced refugees in more ways than one(Credit: The Maggie Program)

The problem: What happens to refugees who are displaced from their homes? Many of them end up staying in camps, often for as long as 12 years. Most host countries only allow temporary structures, which take the form of tents, leading to all kinds of health and social problems as these makeshift shelters are unable to accommodate organizations like schools or hospital wards.

The solution: How do you build a tent with the durability and insulation of a fixed building? Belgian non-profit The Maggie Program has done just that with the Maggie Shelter. Its canvas shell comes with a hollow roof and walls that can be filled with "free, available materials" at the site – including earth, sand and plastic waste – for stability, insulation and noise reduction. Designed to be an all-climate multi-purpose construction, Maggies can double up as schools, medical wards and vocational training centers in places where fixed buildings are not allowed, thus bringing stability and dignity to the lives of refugees. Each shelter, which can accommodate up to 60 people, can be assembled by a team of five to six in two days.

This protective floor covering can reduce parasitic infections by as much as 78 percent(Credit: The Good Works Studio)

The problem: Refugee tents are a hotbed of disease owing to their lack of proper flooring. There is often nothing separating the occupants from the dirt on the ground, which leads to other life-threatening conditions such as hypothermia.

How it helps: Emergency Floor is a modular insulated flooring system that is designed to sit on top of shipping pallets, an abundant, free and underutilized resource, to protect users from the flooding, freezing temperatures and infected soil. It can be installed in a matter of minutes and can also be used directly on the ground or on top of sand bags.

Prototypes of the product have been tested in Sweden in partnership with the IKEA Foundation's Better Shelter program and there are future plans to bring it to camps in Iraq and Nepal.